Cerebrospinal fluid levels of chitinase 3-like 1 and neurofilament light chain predict multiple sclerosis development and disability after optic neuritis.

BACKGROUND: Cerebrospinal fluid (CSF) biomarkers have been suggested to predict multiple sclerosis (MS) after clinically isolated syndromes, but studies investigating long-term prognosis are needed. OBJECTIVE: To assess the predictive ability of CSF biomarkers with regard to MS development and long-term disability after optic neuritis (ON). METHODS: Eighty-six patients with ON as a first demyelinating event were included retrospectively. Magnetic resonance imaging (MRI), CSF leukocytes, immunoglobulin G index and oligoclonal bands were registered. CSF levels of chitinase-3-like-1, osteopontin, neurofilament light-chain, myelin basic protein, CCL2, CXCL10, CXCL13 and matrix metalloproteinase-9 were measured by enzyme-linked immunosorbent assay. Patients were followed up after 13.6 (range 9.6-19.4) years and 81.4% were examined, including Expanded Disability Status Scale and MS functional composite evaluation. 18.6% were interviewed by phone. Cox regression, multiple regression and Spearman correlation analyses were used. RESULTS: Forty-six (53.5%) developed clinically definite MS (CDMS) during follow-up. In a multivariate model MRI (p=0.0001), chitinase 3-like 1 (p=0.0033) and age (p=0.0194) combined predicted CDMS best. Neurofilament light-chain predicted long-term disability by the multiple sclerosis severity scale (p=0.0111) and nine-hole-peg-test (p=0.0202). Chitinase-3-like-1 predicted long-term cognitive impairment by the paced auditory serial addition test (p=0.0150). CONCLUSION: Neurofilament light-chain and chitinase-3-like-1 were significant predictors of long-term physical and cognitive disability. Furthermore, chitinase-3-like-1 predicted CDMS development. Thus, these molecules hold promise as clinically valuable biomarkers after ON as a first demyelinating event.

Chemokine receptor CCR5 in interferon-treated multiple sclerosis.

OBJECTIVE: To study the relationship between CC chemokine receptor CCR5 expression and disease activity in multiple sclerosis (MS) patients treated with beta-interferon (IFN-beta). METHODS: The CCR5 Delta32 allele and a CCR5 promoter polymorphism associated with cell surface expression of CCR5 were analyzed in 109 patients with relapsing-remitting MS treated with IFN-beta who were followed clinically for 1 year. Cellular CCR5 expression was measured by flow cytometry. RESULTS: Patients with MS had a higher percentage of CCR5-positive monocytes than healthy controls. Increased monocyte expression of CCR5 correlated weakly with an increased short-term relapse risk but there was no relationship between CCR5 Delta32 allele and CCR5 promoter polymorphism genotypes and relapse risk. CONCLUSIONS: The results do not support a major role of CCR5 in the pathogenesis of relapses in MS patients treated with IFN-beta, but it is possible that monocyte CCR5 expression may be used as a marker of disease activity.

CD26 + CD4 + T cell counts and attack risk in interferon-treated multiple sclerosis.

Biomarkers that allow the identification of patients with multiple sclerosis (MS) with an insufficient response to immunomodulatory treatment would be desirable, as currently available treatments are only incompletely efficacious. Previous studies have shown that the expression of CD25, CD26 and CCR5 on T cells is altered in patients with active MS. We studied the expression of these molecules by flow cytometry in patients followed for six months during immunomodulatory treatment. In interferon (IFN)-beta-treated patients, we found that the hazard ratio for developing an attack was 28 in patients with CD26 + CD4 + T cell counts above median, and this risk was independent of the risk conferred by neutralizing anti-IFN-beta antibodies. CD26 + CD4 + T cell counts may identify patients with MS at increased risk of attack during treatment with IFN-beta.

Optic neuritis: chemokine receptor CXCR3 and its ligands.

AIM: To study the involvement of the chemokine receptor CXCR3 and its ligands (CXCL9/Mig, CXCL10/IP-10, CXCL11/ITAC) in optic neuritis (ON). METHODS: 30 patients with ON and 10 non-inflammatory neurological disease controls were included. The patients underwent a phlebotomy, lumbar puncture, and MRI scan. CXCR3 expression was studied on blood and cerebrospinal fluid (CSF) T cells by flow cytometry. CXCL9, CXCL10, and CXCL11 were measured in plasma and CSF by ELISA. RESULTS: CSF concentrations of CXCL10, but not of CXCL9 and CXCL11, were significantly higher in ON patients than in controls. CSF concentrations of CXCL10 correlated with the CSF leucocyte count in ON patients, and CXCR3 expressing cells were significantly enriched in the CSF. CONCLUSION: These data show that the CSF concentration of the CXCR3 ligand CXCL10 is selectively increased in CSF from ON patients, and CXCR3 positive cells are recruited to the subarachnoid space.

Chemokine CCL2 and chemokine receptor CCR2 in early active multiple sclerosis.

The chemokine monocyte chemoattractant protein (MCP)-1/CCL2 and its receptor CCR2 have been strongly implicated in disease pathogenesis in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis (MS), whereas data on the CCL2-CCR2 axis are scarce in MS. We studied the expression of CCR2 on leukocytes in blood and cerebrospinal fluid (CSF) from patients with monosymptomatic optic neuritis and MS, and the concentration of CCL2 in the CSF from these patients. Results were compared with the results in non-inflammatory neurological controls and were correlated with other parameters (magnetic resonance imaging and CSF data). Our findings suggest a limited role for CCL2/CCR2 in early active MS.

Respiratory syncytial virus infection--risk factors for hospital admission: a case-control study.

UNLABELLED: Most infants are infected with respiratory syncytial virus (RSV) during the first 2 y of life. The majority have only a mild upper respiratory tract infection, but 1-2% develop a more severe illness and are admitted to hospital. AIM: To carry out a study of risk factors for hospital admission because of RSV infection in Denmark in children aged less than 2 y of age. METHODS: The study population included all 1252 children admitted to hospital with verified RSV infection in two Danish counties during the 5-y period 1990-1994. The investigation comprised a retrospective case-control study with five matched controls per case. In a multivariate analysis the risk factors included medical and demographic variables, and in infants <3 mo of age at hospitalization, two aspects of innate immunity: mannose-binding lectin (MBL) concentration and maternal RSV serum antibody titre, measured on eluates from stored dried blood from the infants' 4th day of life. The effect of each risk factor is expressed as an odds ratio, corresponding to the relative risk of being a case rather than a control if the risk factor is present. RESULTS: The following independent risk factors were identified: age, sex, month of birth, gestational age, birthweight, presence of a sibling, up to 5 y older than the case, and maternal smoking during pregnancy. There was a marginal effect of maternal RSV antibody levels, but no effect of neonatal serum MBL concentration or of crowding in the household. CONCLUSIONS: Ninety percent of cases and 80% of controls had one or more risk factors. Even though several factors were found to increase the risk for hospitalization for RSV disease, all the effects were small and no single specific factor could be identified to explain the hospitalization of the minority of children with RSV infection.

Chemokines and matrix metalloproteinase-9 in leukocyte recruitment to the central nervous system.

Chemokines and matrix metalloproteinases (MMPs) play key roles in leukocyte migration across the blood-brain barrier (BBB) in infectious and inflammatory diseases, including multiple sclerosis (MS). In MS some chemokine receptors are expressed by an increased percentage of T cells in blood, the CSF concentration of chemokine ligands for these receptors is increased, and there is accumulation of T cells expressing relevant chemokine receptors in CSF and in the CNS parenchyma. Chemokine receptor expression patterns appear to reflect disease activity and disease stage in MS. MMPs are constitutively expressed or induced by proinflammatory cytokines and chemokines in leukocytes and CNS-resident cells. Several MMPs are expressed in MS plaques, and the CSF concentration of MMP-9 is increased in MS. The CSF concentration of MMP-9 may reflect disease activity in MS, and the CSF concentration of MMP-9 is higher in patients carrying the MS-associated HLA type DRB1 1501. We review how chemokines and MMP-9 may be involved in the pathogenesis of MS by controlling leukocyte migration between different functional compartments. Measuring expression of these molecules may find use as surrogate markers of disease activity in MS, and interfering with their function holds promise as a novel therapeutic strategy in MS.

Evidence favoring the involvement of CC chemokine receptor (CCR) 5 in T-lymphocyte accumulation in optic neuritis.

OBJECTIVE: To define the relationships between levels of chemokine receptor (CCR)5+ T-cells in blood and cerebrospinal fluid (CSF) of optic neuritis (ON) and control patients (CON). MATERIALS AND METHODS: Expression of CCR5 and related receptors CCR1 and CCR3 on CD4- and CD8-positive T-cells in peripheral blood mononuclear cells (PBMC) and CSF was determined by flow cytometry in 20 patients with ON, 16 control patients with lumbar spondylosis, 20 healthy controls (HC) and 16 patients with rheumatoid arthritis (RA). RESULTS: CCR5+CD4+ and CD8+ T-cells were enriched in CSF, compared with PBMC, in both ON and CON patients (all P < 0.001), and the percentages of CD4+/CCR5+ (r = 0.917) and CD8+/CCR5+ (r = 0.828) cells in PBMC and CSF were strongly and directly correlated. CCR5+ T-cells produce high amounts of tumor necrosis factor-alpha (TNF-alpha) and very low amounts of interleukin-5 (IL-5). Closely related receptors (CCR1, CCR3) were not altered. CONCLUSIONS: Our data suggest an involvement of CCR5 in T-cell accumulation in the inflamed central nervous system.

Prevalence of resistance to ampicillin, gentamicin and vancomycin in Enterococcus faecalis and Enterococcus faecium isolates from clinical specimens and use of antimicrobials in five Nordic hospitals.

We determined the species distribution and prevalence of ampicillin resistance, high-level gentamicin resistance (HLGR) and vancomycin resistance among clinical enterococcal isolates from five Nordic laboratories (Bergen, Tromsø, Uppsala, Aarhus and Reykjavik). Isolates represented three different groups: (i) all blood culture isolates from 1999; (ii) consecutive in-patient isolates (maximum 40); and (iii) consecutive outpatient isolates (maximum 40) collected during March to May 2000. Antimicrobial use data were collected at the national and hospital level. A high proportion (31.4%) of Enterococcus faecium was detected among blood culture isolates, in contrast to only 4.2% among isolates from outpatients. Ampicillin resistance was not found in Enterococcus faecalis, in contrast to 48.8% in E. faecium isolates. HLGR rates varied considerably between laboratories (1.1-27.6%). Acquired vancomycin resistance was not detected. There were no significant differences in the prevalences of HLGR between in-patient and outpatient isolates at individual hospitals. A cluster of clonally related ampicillin-resistant and HLGR E. faecium isolates was demonstrated in one of the hospitals. The lowest level of hospital antimicrobial use, the lowest proportion of E. faecium and the lowest prevalence of resistance were observed in Reykjavik. The study showed a relatively low level of resistance in enterococci, as compared with most European countries and the USA. However, there were large differences between hospitals with regard to the relative proportion of E. faecium isolates, their susceptibility to ampicillin and gentamicin, as well as the prevalence of HLGR in E. faecalis isolates. This indicates a potential for further improvement of antibiotic policies, and possibly hospital infection control, to maintain the low resistance levels observed in these countries.

T-cells in the cerebrospinal fluid express a similar repertoire of inflammatory chemokine receptors in the absence or presence of CNS inflammation: implications for CNS trafficking.

It is believed that chemokines and their receptors are involved in trafficking of T-cells to the central nervous system (CNS). The aim of the current study was to define the expression on cerebrospinal fluid (CSF) T-cells of six chemokine receptors associated with trafficking to sites of inflammation. Flow cytometry was used to detect chemokine receptor expression. We observed that CD3+T-cells in the CSF express a restricted array of inflammatory chemokine receptors, specifically CXCR3, CCR5 and CCR6, but little CCR1-3. This repertoire was independent of the presence of CNS inflammation, since comparable findings were obtained in patients with multiple sclerosis (MS) and individuals with non-inflammatory neurological diseases. The enrichment of CCR5+T-cells in the CSF could largely be explained by higher frequency of CD4+/CD45RO+T-cells in this compartment. In contrast, CD4+/CD45RO+T-cells expressing CXCR3 were significantly enriched in CSF as compared with blood. Similar levels of CCR6+/CD3+T-cells were observed in blood and CSF, while levels of CCR2+/CD3+T-cells were lower in CSF than in blood. The CSF was virtually devoid of CCR5+/CXCR3- T-cells, suggesting that the expression of CCR5 alone is not sufficient for the trafficking of CD3+T-cells to the CSF. We hypothesize that CXCR3 is the principal inflammatory chemokine receptor involved in intrathecal accumulation of T-cells in MS. Through interactions with its ligands, CXCR3 is proposed to mediate retention of T-cells in the inflamed CNS.

Selective suppression of chemokine receptor CXCR3 expression by interferon-beta1a in multiple sclerosis.

We studied the expression of chemokine receptors CCR1, CCR2, CCR3, CCR5, and CXCR3 on CD4 and CD8 positive T cells, and on CD14 positive monocytes in blood from 10 patients with relapsing-remitting multiple sclerosis (MS) at initiation of interferon (IFN)-beta treatment, after 1 month and after 3 months of treatment. It was found that the expression of CXCR3 on CD4+ and CD8+ T cells was significantly reduced after 3 months of treatment. The expression of other receptors was unaltered. Since CXCR3 cells are enriched in cerebrospinal fluid (CSF), and are detected in lesion material in MS this may represent an important mode of action of interferon-beta in MS.

CCR1+/CCR5+ mononuclear phagocytes accumulate in the central nervous system of patients with multiple sclerosis.

Mononuclear phagocytes (monocytes, macrophages, and microglia) are considered central to multiple sclerosis (MS) pathogenesis. Molecular cues that mediate mononuclear phagocyte accumulation and activation in the central nervous system (CNS) of MS patients may include chemokines RANTES/CCL5 and macrophage inflammatory protein-1alpha/CCL3. We analyzed expression of CCR1 and CCR5, the monocyte receptors for these chemokines, on circulating and cerebrospinal fluid CD14+ cells, and in MS brain lesions. Approximately 70% of cerebrospinal fluid monocytes were CCR1+/CCR5+, regardless of the presence of CNS pathology, compared to less than 20% of circulating monocytes. In active MS lesions CCR1+/CCR5+ monocytes were found in perivascular cell cuffs and at the demyelinating edges of evolving lesions. Mononuclear phagocytes in early demyelinating stages comprised CCR1+/CCR5+ hematogenous monocytes and CCR1-/CCR5- resident microglial cells. In later stages, phagocytic macrophages were uniformly CCR1-/CCR5+. Cultured in vitro, adherent monocytes/macrophages up-regulated CCR5 and down-regulated CCR1 expression, compared to freshly-isolated monocytes. Taken together, these findings suggest that monocytes competent to enter the CNS compartment derive from a minority CCR1+/CCR5+ population in the circulating pool. In the presence of ligand, these cells will be retained in the CNS. During further activation in lesions, infiltrating monocytes down-regulate CCR1 but not CCR5, whereas microglia up-regulate CCR5.

Distinct chemokine receptor and cytokine expression profile in secondary progressive MS.

BACKGROUND: Chemokines, small chemotactic cytokines, have been implicated in active relapsing-remitting MS (RRMS). However, the role of chemokines and chemokine receptors has not been specifically studied in secondary progressive MS (SPMS). METHODS: Fifteen patients with SPMS, 15 patients with relapses of RRMS, 10 patients with RRMS in remission, and 20 healthy controls were included in this study. The expression of CC chemokine receptor 1(CCR1), CCR2, CCR3, CCR5, and CXC chemokine receptor 3(CXCR3) was studied on leukocyte subsets using flow cytometry, and the cytokine profile of T cells expressing CCR2 and CCR5 was determined. The authors also studied the effect of treatment with interferon-beta-1b on the expression of chemokine receptors in SPMS. RESULTS: The authors found a significantly higher percentage of CCR2-expressing T cells in SPMS than in the other patients groups. CCR2-positive T cells produced high levels of interleukin (IL)-5 and low levels of tumor necrosis factor alpha, indicating a T-helper type 2 (Th2)/T-cytotoxic type 2 (Tc2) profile of these cells. The expression of CCR5, a chemokine receptor associated with Th1 responses, was significantly lower in SPMS than in patients with active RRMS. Interferon (IFN) beta-1b treatment in SPMS did not alter chemokine receptor expression in SPMS. CONCLUSION: The authors find qualitative differences in the systemic inflammatory response in RRMS and SPMS, indicating a distinct inflammatory environment in SPMS. Chemokine receptor expression in SPMS did not change after treatment with IFN beta-1b. It remains to be established if these findings reflect differences between RRMS and SPMS in effector or regulatory mechanisms.

Transient intestinal carriage after ingestion of antibiotic-resistant Enterococcus faecium from chicken and pork.

BACKGROUND: Antibiotic-resistant enterococci are often present in retail meats, but it is unclear whether the ingestion of these contaminants leads to sustained intestinal carriage. METHODS: We conducted a randomized, double-blind study in 18 healthy volunteers. Six ingested a mixture of 10(7) colony-forming units (CFU) of two glycopeptide-resistant strains of Enterococcus faecium obtained from chicken purchased at a grocery store, six ingested 10(7) CFU of a streptogramin-resistant strain of E. faecium obtained from a pig at slaughter, and six ingested 10(7) CFU of a glycopeptide-susceptible and streptogramin-susceptible strain of E. faecium from chicken purchased at a grocery store. Suspensions of enterococci were prepared in 250 ml of whole milk and were well within the amounts deemed acceptable by Danish food regulations. Stool samples were collected before exposure, daily for 1 week after ingestion, and at 14 and 35 days. Resistant enterococci in stools were identified by selective culture techniques; further molecular characterization of the organisms was also conducted. RESULTS: At the outset, none of the subjects were colonized with glycopeptide-resistant or streptogramin-resistant E. faecium. After ingestion of the study strains, these same strains were isolated from the stools of all subjects, in various concentrations. The test strain was isolated in stool from 8 of 12 subjects on day 6, and from 1 of 12 on day 14. All stool samples were negative at 35 days. CONCLUSIONS: The ingestion of resistant E. faecium of animal origin leads to detectable concentrations of the resistant strain in stools for up to 14 days after ingestion. The organisms survive gastric passage and multiply.

Importance of transmembrane segment M3 of the sarcoplasmic reticulum Ca2+-ATPase for control of the gateway to the Ca2+ sites.

The specific functional roles of various parts of the third transmembrane segment (M3) of the sarcoplasmic reticulum Ca(2+)-ATPase were examined by functionally characterizing a series of mutants with multiple or single substitutions of M3 residues. Steady-state and transient kinetic measurements, assisted by computer simulation of the time and Ca(2+) dependences of the phosphorylation level, were used to study the partial reaction steps of the enzyme cycle, including the binding and dissociation of Ca(2+) at the high affinity cytoplasmically facing sites. The mutation Lys-Leu-Asp-Glu(255) --> Glu-Ile-Glu-His resulted in a conspicuous increase in the rate of Ca(2+) dissociation as well as a displacement of the major conformational equilibria of the phosphoenzyme and dephosphoenzyme forms. The point mutant Phe(256) --> Ala also showed an increased rate of Ca(2+) dissociation, whereas a conspicuous decrease both in the rate of Ca(2+) dissociation and in the rate of Ca(2+) binding was found for the mutant Gly-Glu-Gln-Leu(260) --> Ile-His-Leu-Ile. These findings suggest that the NH(2)-terminal half of M3 is involved in control of the gateway to the Ca(2+) sites. The main effect of two mutations to the COOH-terminal half of M3, Ser-Lys-Val-Ile-Ser(265) --> Thr-Gly-Val-Ala-Val and Leu-Ile-Cys-Val-Ala-Val-Trp-Leu-Ile(274) --> Phe-Leu-Gly-Val-Ser-Phe-Phe-Ile-Leu, was a block of the dephosphorylation.

The patient, their doctor, the regulator and the profit maker: conflicts and possible solutions.

The dilemmas and conflicts between industry, who develop and market antibiotics and the regulators who are responsible for regulating their use to preserve efficacy are explored. Despite regulations, the industry remains profitable and should concentrate more on development of innovative products which readily gain market share without excessive marketing. Various aspects of regulations are discussed as they influence the prescriber and the patient.